The present invention relates generally to hermetic compressor assemblies and, more particularly, to compressors that are divided into separate discharge or high pressure and suction or low pressure sections.
Hermetic compressors comprise a hermetically sealed housing having a compressor mechanism, motor, and various related parts mounted therein. The compressor mechanism typically includes a crankcase, also referred to as a cylinder block in rotary and reciprocating piston type compressors, which defines at least one compression chamber in which gaseous refrigerant is compressed and subsequently discharged into a common discharge cavity. Suction gas at low pressure is drawn into the housing of the compressor and is delivered to the compressor mechanism where the suction gas is compressed by the reciprocating piston in the cylinder and discharged at discharge pressure into a discharge cavity and ultimately out of the compressor housing. Gas at suction pressure is maintained separate from the discharge gas. Some compressors are referred to as high-side units, in which the housing is generally at discharge or high pressure, i.e. discharge gas occupies the space defined by the housing. Other compressors are referred to as low-side units, in which the housing is generally at suction or low pressure, i.e. suction gas occupies the space defined by the housing. Although high side machines offer a more attractive environment from the standpoint of flow of lubricating oil throughout the compressor, a problem associated with high side machines is that with the motor surrounded by high temperature discharge gas, the operating efficiency of the motor and the compressor are lessened.